It is often said that prevention is the best medicine — and that’s especially true for pet vaccinations.

No pet owner wants to see a furry friend get sick, and as an added bonus, vaccinations are far less expensive than treating a disease.  

Pet Vaccines 101

Vaccines contain either partial or weakened versions of viruses and/or bacteria. Your pet’s immune system reacts to these antigens and creates antibodies. Once your pet’s immune system learns how to fight the virus or bacteria, the pet’s body can fight it off if it comes in contact with that same pathogen again. Over time, however, the effect of the vaccine grows weaker, which is why booster shots are needed to keep your pet safe. 

Some vaccinations are dependent on a cat’s or dog’s specific needs, like lifestyle and geographic location. These optional vaccines are called non-core vaccines. Your local veterinarian can advise you regarding what non-core vaccines your pet should receive. Within a 35-mile radius of Blacksburg, please consider utilizing the services of Small Animal Community Practice (CPRAC) at the Veterinary Teaching Hospital within the Virginia-Maryland College of Veterinary Medicine for your pet’s vaccination needs.

The American Animal Hospital Association (AAHA) recommends core feline and canine vaccines that  all cats and dogs should  receive.

Core Vaccines for Cats and Dogs

The rabies vaccine is a core vaccine for both cats and dogs, and 39 different states require that cats and dogs be vaccinated against rabies. Virginia requires rabies vaccination for cats and dogs over the age of four months. 

Rabies is spread through contact with saliva, typically through a bite from an infected animal. There is no treatment for rabies in animals or in humans once symptoms occur; rabies has a fatality rate of nearly 100%. There are two forms of rabies. With furious rabies, the animal becomes aggressive and irritable, and with paralytic rabies (aka dumb rabies), the animal loses muscle control and the throat and jaw become paralyzed. Rabid animals die of seizures or fall into a coma that leads to death. Thankfully, the rabies vaccine is highly effective in keeping pets safe against rabies.

Other than rabies, the AAHA recommends that every dog be vaccinated against the following viruses:

  • Canine distemper, an airborne virus that can also be transmitted through shared water bowls and other shared surfaces. Respiratory and gastrointestinal symptoms like pneumonia and diarrhea are followed by neurologic complications, including seizures. In some cases, the neurologic signs continue even after other signs are gone. In some cases, this virus can be treated, but it still has a very high mortality rate.
  • Adenovirus type 2 (CAV-2), which also protects dogs from type 1. Adenovirus causes hepatitis (inflammation of the liver) in dogs and is spread through contact with infected urine and nose and eye discharge. Adenoviruses cause a cough as well as eye and nasal discharge. Particularly dangerous for younger dogs, adenoviruses can cause fever, swelling under the skin, diarrhea, and vomiting in severe cases. 
  • Parvovirus, also known as “parvo,” is another highly contagious virus. Parvovirus is spread through contact with other dogs, contaminated feces, and even the environment. The virus can spread through many sources  — including people’s hands and clothes. Most deaths from parvovirus occur within two to three days of symptoms, which include vomiting, severe diarrhea (often bloody), fever, abdominal pain, and lethargy. 
  • Parainfluenza, a virus that causes respiratory disease, and is one of the pathogens that causes kennel cough. Not only does parainfluenza cause coughing, it suppresses the immune system, making the dog more susceptible to other infections, like pneumonia. 

For cats, the AAHA recommends vaccination against the following:

  • Feline herpesvirus-1 (FHV-1) , a virus spread through saliva as well as the eye and nose discharges of infected cats.Cats can also come into contact with the virus through contaminated surfaces. In addition to being the most common cause of conjunctivitis in cats, the virus is a major cause of upper respiratory disease, causing sneezing, coughing, nasal discharge, and fever. 
  • Feline panleukopenia virus, also known as feline distemper or feline parvovirus, is a virus that affects kittens most severely. The virus can survive for up to a year in the environment and is resistant to many disinfectants. The virus causes damage to the lining of the intestines, the lymph nodes, and bone marrow, resulting in shortages of white and red blood cells. Symptoms include a high fever, lethargy and depression, severe diarrhea, and dehydration. The virus can also damage the brains and eyes of kittens. 
  • Calicivirus, another virus that causes upper respiratory diseases in cats. In addition to upper respiratory symptoms and conjunctivitis, calicivirus can cause ulcers on the roof of the mouth, the tongue, nose, gums, or lips. Some cats with calicivirus also develop pain in one or more joints.
  • Feline leukemia, a virus that affects the immune system. This vaccine is suggested for all cats under one year of age that do not already carry antibodies against the virus because they are the most likely to be infected if exposed to the virus. Young cats can carry antibodies they received through the mother’s milk, or from transient infection, so their status should always be confirmed before vaccination. Feline leukemia is one of the most common infectious diseases in cats, though it has become far less prevalent over the past few decades thanks to effective vaccines and tests. Causing immune deficiency, it is the most common cause of cancer in cats and may cause blood disorders. Because the virus affects the immune system, cats with feline leukemia can’t properly fight off other diseases.

The Value of Vaccines

Complications from vaccines are very rare, and side effects tend to be mild, such as swelling at the injection site. In cats, the inflammation from vaccination has been known to cause sarcomas. However, this is very uncommon, occurring in one out of every 10,000-30,000 vaccinations. Furthermore, many feline vaccines have been modified to remove the majority of agents that resulted in injection site sarcomas.

Veterinary professionals agree that the benefits of vaccination far outweigh the risks. Widespread vaccination has helped save millions of animals from death and disease, and because of vaccines, many deadly diseases have become rare. 

“Vaccines are remarkably safe and effective, and truly protect our beloved four-legged companions against significant, often fatal, diseases,” said Mark Freeman, clinical associate professor of community practice at the Veterinary Teaching Hospital. “The benefits far outweigh the risks, and each pet’s vaccine needs can be tailored to their specific risk for infection.”

If you’re a pet owner, talk with your veterinarians to ensure that your pet gets the vaccinations they need to lead a long, healthy life.

Written by Sarah Boudreau M.F.A. '21, a writer with the Virginia-Maryland College of Veterinary Medicine


Andrew Mann
Director of Communications and Marketing